In the bustling kitchen of his childhood home in Brazil, while his single mother rushed to prepare meals for four children before work, young Pablo Peixoto bombarded her with an endless stream of questions. “I was that annoying kid who wouldn’t stop asking ‘what?,’ ‘why?,’ and ‘how?,’” he recalls. This insatiable curiosity extended from the kitchen to the classroom, where he peppered teachers and peers with questions during lessons or presentations, and has since carried him through to his career as a biophysicist. “I stopped asking why, but I kept asking what and how.”
Pablo Peixoto’s journey began far from the ivory towers of academia. His childhood was spent moving around Brazil, from a shanty home in Sobradinho to the outskirts of Brasília, and to Rondônia in the Amazonian region, from where his mother had migrated as part of the candango wave that built Brazil’s capital. The family eventually settled in Uberlândia, where he would come of age and begin his academic journey. Peixoto was the first in his family to attend college, though he notes that he was inspired to study science by his uncle, Chico: “In another life he might have been an engineer,” Peixoto reflects. His mother cleaned houses during his childhood, later starting a business and eventually earning her high school diploma and a degree in history. She now works as an elementary school administrator.
At the Universidade Federal de Uberlândia, Peixoto began his scientific career in an ecology and animal behavior laboratory under Kleber Del Claro, studying the complex tripartite interactions between ants, aphids, and plants. His research focus then shifted to the honeybee brain, where he investigated myosins under the mentorship of Foued Salmen Espíndola, who would guide both his undergraduate and master’s theses.
The pivotal moment that would set him down his career path came during his senior year. When he discovered a flier from the Agencia Española de Cooperación Internacional para el Desarrollo (AECID) advertising research internships across Spain, one opportunity stood out—not for its appeal, but for its apparent lack thereof. “I applied for the one I assumed no one else would want: Mitochondrial Electrophysiology at the Universidad de Extremadura in Cáceres,” he explains. “I thought the title sounded intimidating and that people would rather pick Barcelona, Madrid, Salamanca, or Seville.”
This calculated gamble paid off spectacularly. Cáceres, as Peixoto puts it, “became my point of no return.” The internship introduced him to the fascinating world of mitochondrial electrophysiology and to Marisa Campo, whom he fondly refers to as one of his two “scientific mothers.” After briefly returning to Brazil to complete his master’s degree, he secured a CAPES-Humboldt Research Fellowship to return to Cáceres for his PhD under Campo’s guidance.
His doctoral work established him as an expert in patch-clamping mitochondria, a rare and technically demanding skill that would prove invaluable throughout his career. This expertise caught the attention of Casey Kinnally at the New York University College of Dentistry, who would become his second “scientific mother.” Despite not having published his thesis work at the time, Kinnally recognized Peixoto’s potential and recruited him for postdoctoral research.
“It was serendipity,” Peixoto says of his entry into mitochondrial biophysics. “That AECID internship opened the door, but I stayed because Marisa and Casey saw something in me and nurtured it. I became a mitochondriac and never looked back.” The term “mitochondriac”—a playful portmanteau of mitochondria and maniac—perfectly captures Peixoto’s enthusiasm for these cellular powerhouses.
In Kinnally’s lab, Peixoto dove into cancer research, studying how mitochondria release apoptotic signals and how this crucial process fails in malignant cells. “At the time, I had not yet published a paper from my thesis, but I had a rare technical skill and she gave me a chance to prove myself,” he recalls. That chance paid dividends: Five years and twelve papers later, he had established himself as a formidable researcher and moved to a new postdoc position in Giovanni Manfredi’s laboratory at Weill Cornell, where he expanded his expertise from electrophysiology into metabolism. “Giovanni brought me in for patch clamping, but I left with a solid foundation in metabolism, thanks to working closely with Anatoly Starkov and others in the lab,” he notes.
Today, Peixoto serves as an associate professor of biology in the Department of Natural Sciences at Baruch College, City University of New York—“It’s a mouthful, and I love it, just like my full name: Pablo Marco Veras Peixoto,” he quips.
Peixoto’s current research sits at the intersection of cellular biophysics and neuroscience. His lab studies mitochondrial hydrogen peroxide signaling in synaptic function and plasticity, work that has yielded surprising insights into how neurons communicate and adapt. “We recently showed that mitochondrial H₂O₂ is released during normal synaptic activity and that high-frequency stimulation enhances its release to drive plasticity,” he describes. Using an optogenetic fly model, his team demonstrated that simply turning on H₂O₂ release from presynaptic mitochondria was sufficient to induce plasticity without stimulation.
Like many scientists, Peixoto has faced times of doubt and adversity. “I’ve had moments when I questioned my path or felt everything was at risk,” he reveals. “Some of these challenges were acute, others accumulated over time.” Although he developed resilience through these trials, the most significant challenge came after achieving a major milestone: tenure. “I had reached the goal I had chased for years, but I was still overworked, anxious, and running on empty,” he reflects. A series of anxiety attacks forced him to confront a pattern he had maintained throughout his career: “I realized I had spent my life focused on the next milestone—graduation, PhD, postdoc, job, tenure, grants—and had neglected my well-being.” With support from his doctor, therapist, husband, and friends, he began to understand that “well-being, like science, requires sustained attention and care.”
When asked about the most rewarding aspect of his work, he recounts receiving a photo from Ma Su Su Aung, a former student, at her neurology fellowship graduation. “I replied with one from her college graduation,” he says. “Seeing what students go on to achieve, and knowing I played a small part in their journey, makes this the best job in the world.”
Peixoto sees exciting developments ahead for biophysics, noting that “some people are now using it to tackle deeply subjective questions like consciousness.” In his own research area, he’s eager to measure emerging and unknown mitochondrial signals in real time during neuronal firing. “There are huge technical hurdles, but the questions are ripe,” he asserts.
Throughout his career, BPS has been his home society, offering support and community at each stage. “I say I ‘grew up’ in the Society, and I mean it. I work at a primarily undergraduate institution with a small but growing research footprint,” he shares. “Being part of BPS helps me think big. It keeps me connected, engaged, and inspired, and it’s been a place where my students find the same support I did back in 2004.”
Asked what he finds special about the Biophysical Society, Peixoto offers, “The Subgroups have my heart, especially Bioenergetics, Mitochondria, and Metabolism. I also love the SoBLA [Sociedad de Biofísicos Latinamericanos] meetings, which happen late on Tuesday nights at the Annual Meeting and often include Society leadership showing up to support Latin American biophysicists.”
Outside the laboratory, Peixoto maintains a rich life that includes reading science fiction and nonfiction, practicing yoga, spending time in psychoanalysis, scuba diving, rock climbing, and attending the opera. This diverse array of interests speaks to the same curiosity that drove him to science.
For young scientists entering the field, Peixoto’s advice is characteristically direct and encouraging: “Join a committee, a Subgroup, Black in Biophysics, SoBLA, student chapters. Go to the microphone. Ask the question.” It’s advice that reflects his own journey from that curious child asking endless questions in his mother’s kitchen to a respected researcher unraveling the mysteries of cellular communication.